Polarizing lenses are often employed as lenses for nonprescription sunglasses (including fashion glasses) to protect the eyes because they function to block light. They are also employed as prescription eyeglass lenses.
The polarizing lenses described in Japanese Unexamined Patent Publication (KOKAI) Nos. 2009-3303 and 2012-198389 (which are expressly incorporated herein by reference in their entirety) are polarizing lenses with polarizing films embedded within them. They are manufactured by casting a curable composition around a polarizing film, heating, and curing (called the casting method or casting polymerization method).